git-annex/Logs/SingleValue.hs
Joey Hess e213ef310f git-annex (5.20140717) unstable; urgency=high
* Fix minor FD leak in journal code. Closes: #754608
  * direct: Fix handling of case where a work tree subdirectory cannot
    be written to due to permissions.
  * migrate: Avoid re-checksumming when migrating from hashE to hash backend.
  * uninit: Avoid failing final removal in some direct mode repositories
    due to file modes.
  * S3: Deal with AWS ACL configurations that do not allow creating or
    checking the location of a bucket, but only reading and writing content to
    it.
  * resolvemerge: New plumbing command that runs the automatic merge conflict
    resolver.
  * Deal with change in git 2.0 that made indirect mode merge conflict
    resolution leave behind old files.
  * sync: Fix git sync with local git remotes even when they don't have an
    annex.uuid set. (The assistant already did so.)
  * Set gcrypt-publish-participants when setting up a gcrypt repository,
    to avoid unncessary passphrase prompts.
    This is a security/usability tradeoff. To avoid exposing the gpg key
    ids who can decrypt the repository, users can unset
    gcrypt-publish-participants.
  * Install nautilus hooks even when ~/.local/share/nautilus/ does not yet
    exist, since it is not automatically created for Gnome 3 users.
  * Windows: Move .vbs files out of git\bin, to avoid that being in the
    PATH, which caused some weird breakage. (Thanks, divB)
  * Windows: Fix locking issue that prevented the webapp starting
    (since 5.20140707).

# imported from the archive
2014-07-17 11:27:25 -04:00

65 lines
1.7 KiB
Haskell

{- git-annex single-value log
-
- This is used to store a value in a way that can be union merged.
-
- A line of the log will look like: "timestamp value"
-
- The line with the newest timestamp wins.
-
- Copyright 2014 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Logs.SingleValue where
import Common.Annex
import qualified Annex.Branch
import qualified Data.Set as S
import Data.Time.Clock.POSIX
import Data.Time
import System.Locale
class SingleValueSerializable v where
serialize :: v -> String
deserialize :: String -> Maybe v
data LogEntry v = LogEntry
{ changed :: POSIXTime
, value :: v
} deriving (Eq, Show, Ord)
type Log v = S.Set (LogEntry v)
showLog :: (SingleValueSerializable v) => Log v -> String
showLog = unlines . map showline . S.toList
where
showline (LogEntry t v) = unwords [show t, serialize v]
parseLog :: (Ord v, SingleValueSerializable v) => String -> Log v
parseLog = S.fromList . mapMaybe parse . lines
where
parse line = do
let (ts, s) = splitword line
date <- utcTimeToPOSIXSeconds <$> parseTime defaultTimeLocale "%s%Qs" ts
v <- deserialize s
Just (LogEntry date v)
splitword = separate (== ' ')
newestValue :: Log v -> Maybe v
newestValue s
| S.null s = Nothing
| otherwise = Just (value $ S.findMax s)
readLog :: (Ord v, SingleValueSerializable v) => FilePath -> Annex (Log v)
readLog = parseLog <$$> Annex.Branch.get
getLog :: (Ord v, SingleValueSerializable v) => FilePath -> Annex (Maybe v)
getLog = newestValue <$$> readLog
setLog :: (SingleValueSerializable v) => FilePath -> v -> Annex ()
setLog f v = do
now <- liftIO getPOSIXTime
let ent = LogEntry now v
Annex.Branch.change f $ \_old -> showLog (S.singleton ent)